1. Field of the Invention
The present invention relates to topical over-the-counter and prescription strength analgesic and antiphlogistic blended compositions which are useful for reducing inflammation and providing relief from both peripheral and central pain as well as to a flexible therapeutic wrap for topical delivery of said blended compositions. More particularly, the invention is a blended composition comprising from about 3% to about 30% by weight of extract of arnica montana in combination with an effective amount of one or more therapeutic or pharmaceutical agents selected from the group consisting of menthol crystal, camphor, oil of mint, eucalyptus oil, guaifenesin, non-steroidal anti-inflammatory medications, topical analgesics, or transdermal opioid analgesics blended in either a pluronic lecithin organogel (PLO) or a petrolatum base. The particular agents selected and the percent composition of each selected ingredient in a given blend being determined by the needs and sensitivities of the given patient.
2. Background of the Invention
A wealth of problems are known to be associated with the oral ingestion of pharmaceutical agents. For instance, due to sensitivities, many patients experience gastrointestinal irritation and intolerance from a single dose. Many others develop such intolerance as a result of prolonged treatment or develop other more severe gastrointestinal irritations such as ulceration. Further, patients present with widely differing metabolisms resulting in unpredictably variable rates of absorption. In addition, any oral treatment carries with it often unpredictable risks for side effects.
The risks and problems associated with oral introduction of medication are magnified when treating chronic pain such as peripheral neuropathic pain associated with diseases such as diabetes melitis, chronic renal failure, myeloma, cancer, and hypothyroidism. Repeated doses of oral medication are known to compound any negative effect on the stomach and intestinal tract. Moreover, many of the patients suffering from chronic illnesses are senior citizens who are even more susceptible to the risks and side effects from oral medication. Similarly, when a child presents with acute or chronic illness, it is particularly desirable to avoid the risks of side effects and the damage caused from repeated ingestion of medication.
Additionally, many pain medications and muscle relaxants given orally have undesirable effects on cognition and level of consciousness. A patient who suffers pain but must work, drive, and/or care for children places himself and others at risk while taking theses medications. These topical preparations allow for pain relief without undue risk of undesired sedation and altered cognition.
Another disadvantage of oral medication is its frequent ineffectiveness in treating specific types of pain such as the phantom limb pain associated with amputations. One explanation for this ineffectiveness is that oral medication provides no stimulation of the nerve endings to disrupt or stimulate the interrupted signal from the limb to the brain.
Delivery of pharmaceutically active agents through the skin avoids many of these risks and disadvantages. For instance, transdermal medication is parenteral, thus avoiding problems related to gastrointestinal irritation. Further, with topical administration, variances in absorption and metabolism rates cease to be a consequential factor and the risk of potential side effects is greatly reduced. In addition to avoiding many of the disadvantages associated with oral ingestion of medication, topical delivery has some distinct and important advantages. First, by medicating through the skin, a more even and continuous dosage of medication may be administered over a longer period of time. Further, such treatment provides more immediate, as well as more physically and psychologically rewarding, relief, as it may be applied directly to site of the pain, whether that pain be local in nature or a generalized pain with local manifestations. As discussed, localized application and sensitization is particularly important in cases involving amputation. Yet, although direct application may be to a local site, the medication is introduced and acts systemically.
In spite of the obvious advantages in providing medications topically, it has been difficult to find compositions and delivery methods which are effective for this purpose due to the nature of skin as a defensive barrier for the body. After all, one of the main functions of skin as an organ of the body is to obstruct toxic materials and pathogens from entering the body while retaining desired physiological fluids and nutrients within the body. For this reason, the skin is highly impermeable, creating a challenge to the percutaneous introduction of pharmaceutically active agents. Thus, a search continues to discover methods of delivery or compositions which will be successful in transporting an effective dosage of medication across this natural barrier.
The problems with topical delivery are really two-fold. First, as just described, there is the challenge of finding a composition and method of application which permits transport across the skin's natural barrier. The second problem is focused on the mechanics of delivering medication to a flexible, mobile, and sensitive surface such as the skin. To encourage a patient's cooperation with systematic and often long-term treatment, pharmaceutical or therapeutic agents must be delivered in a way that will be comfortable and even rewarding to the patient. Further, it is important that the method of delivery ensure that the active agents are kept securely in place against the skin long enough to permit the desired penetration without unduly affecting the patient's mobility. Finally, safety is a concern, particularly when treating pediatric or geriatric patients in whom there is risk of ingestion of the medication or plasticized portions of the wrap.
There have been a variety of approaches suggested for addressing the first of these challenges--enhanced penetration. For instance, it has long been known that the introduction of an electrical charge at the point of transdermal transport may assist the penetration of certain medications. Recent improvement patents in this area are U.S. Pat. No. 4,927,408 to Haak and U.S. Pat. No. 5,080,646 to Theeuwes et al. The basic principle here is to effect the system electrochemically so as to enhance penetration. The disadvantages of such a system, however, are in the need for additional specialized equipment and/or chemicals beyond that which is needed to medicate. These additional requirements bring with them risks and costs.
Another approach for achieving increased penetration of pharmaceutically active agents is through the use of chemical enhancers. An effective amount of these enhancing chemicals are mixed with the desired medicinal agent before it is applied to the skin resulting in more effective penetration. It is taught that these chemical enhancers are effective in speeding and increasing the penetration of the medication due to their chemical similarity to the highly impermeable outer layer of the skin. U.S. Pat. No. 5,482,965 to Rajadhyaksha teaches the use of amino alcohol derivatives to achieve enhanced membrane penetration. Similarly, U.S. Pat. No. 4,557,934 discloses another series of chemicals which are effective for this purpose. Once again, however, as in the use of electrical charge, the use of chemical enhancers has the disadvantage of requiring something in addition to the ingredients needed for treatment. Addition of any medically unnecessary chemical ingredient carries with it an increased risk for reaction.
It would be beneficial, therefore, to discover a therapeutically active ingredient or a combination of ingredients which would accomplish penetration without outside influence. This is particularly needed in the treatment of neuropathic pain of the type associated with conditions such as arthritis or diabetes. Anti-inflammatories and pain killers such as ketoprofen or lidocaine applied topically to an area affected by pain may provide some local relief but there is very little deep penetration of such non-steroidal anti-inflammatory and/or analgesic medications and, therefore, little, if any, relief from more generalized neuropathic pain. The inventors herein have unexpectedly discovered that the extract of an herb called amica montana, in combination with certain other therapeutic agents such as analgesics, warms and increases capillary blood flow to the treatment area, thereby improving absorption of the active ingredients. This synergistic effect results in enhanced penetration of the skin to provide pain relief both for local and diffuse pain conditions such as diabetes or myeloma. Arnica montana (commonly known as mountain tobacco) is an herb which grows on the mountains of Switzerland and is also cultivated elsewhere in the world. The medicinal value of various extracts of the herb has been recognized for centuries in the treatment of numerous illnesses, however, there is no consensus as to the active principle behind its reported effectiveness. Nevertheless, amica montana has been cited as useful in a wide variety of applications. For example, a relatively recent patent to Sawruk, U.S. Pat. No. 5,478,579, teaches a method for inducing and enhancing the absorption of calcium into bone by combining the calcium with an effective dose of flavonol aglycone glycoside. Sawruk identifies arnica montana as a significant source of this chemical component. In this instance, it is opined that the flavonol aglycone glycosides assist in absorption of calcium through a chelation delivery system. Other oral applications of arnica extracts are rare, however, because it has been reported that arnica has a harmful effect on the heart and may also effect the nervous system negatively at high doses.
Topical uses for extracts of arnica montana are, by far, the most common and attribute a wide range of attributes to the herbal extract. For example, the addition of extract of arnica is recommended in U.S. Pat. No. 5,271,942 to Heverhagen which discloses an agent for reducing hair growth on the human body. It is suggested that arnica extract has "astringent, tonic, soothing and wound-healing effects" and should, therefore, be added to the hair reduction agent to compensate for cases of sensitive skin. These same soothing and healing qualities are recognized in U.S. Pat. No. 4,569,839 to Grollier et al. for use in a cosmetic treatment for the hair and skin. Perhaps the most common topical use for arnica is in the treatment of hematomas as taught in U.S. Pat. No. 3,832,343 to Majoie et al. Arnica's effectiveness in this instance is attributed to its effectiveness in preventing coagulation of blood. In Ismail, U.S. Pat. No. 4,938,960, extract of arnica montana is recognized as having the ability to promote blood circulation and is, therefore, a suggestive additive to an agent for treatment and protection of the skin on the theory that the arnica will increase the action of the vitamin E in the composition. Addition of extract of arnica is also taught for a variety of cases where the desired result is a reduction of inflammation and/or edema such as U.S. Pat. No. 5,043,153 to Videki et al. for compositions for the treatment of parodonthopathy and U.S. Pat. No. 4,795,638 to Ayache et al. and U.S. Pat. No. 4,684,522 to Marissal et al., both directed to compositions to reduce adipose swelling and cellulite, inferring an anti-inflammatory characteristic to the herb.
None of these references recognize arnica as useful in enhancing penetration of the skin or as an effective agent in providing neuropathic pain relief. U.S. Pat. No. 5,162,037 to Whitson-Fischman teaches the use of extract of arnica montana as one of many components in an herb-based homeopathic medicament for the treatment of chronic muscular and joint pain. Whitson-Fischman, however, does not specify the role of arnica in the component mix disclosed herein. Further, the method taught in Whitson-Fischman involves delivery of the homeopathic medicant mix in three separate phases: an injectable dose delivered to specified acupuncture points; a topical dose delivered by means of a transdermal patch applied directly over appropriate acupuncture points; and orally. In addition, in each of these delivery methods, the medications delivered to the body are magnetically stimulated at the time of introduction to assist in absorption and effectiveness. The invention herein rests in part on the discovery that extract of arnica montana, in combination with other selected components, warms and increases capillary blood flow, thereby improving absorption of other active ingredients simply through topical delivery according to the proposed delivery method and without the need for other stimulus.
Once penetration and effective pain relief is achieved, the next significant concern in achieving effective topical application is keeping the therapeutic agent comfortably and productively in place for the length of time required to achieve the desired penetration and results. The difficulties here focus on the flexibility of the skin, the mobility of the patient, the sensitivity of the skin, and other related considerations such as sterility and the need to protect clothing and bedding from the medication. For these reasons, it is desirable that topical therapeutic compositions be of a consistency that will easily accommodate the skin's flexibility, yet stay in place as the patient moves about. The consistency of the medicant, therefore, should be pliable but tacky. Further, it is important that the treating composition stay in place for the duration of treatment yet be able to be comfortably removed and cleaned away between treatments. Such a support, whether it be a bandage, patch, or wrap, should be easily removable, offer protection to clothing and bedding, and support the active ingredients in such a way that they achieve the best possible contact with and penetration into the skin. Moreover, it is important that the pharmaceutical composition be sterile and that any bandage or cover placed over the medication is also sterile as well as providing a good support for the therapeutic agents. Finally, safety issues must be addressed. Thus, the medication must be offered in a composition without plastic covering and with low enough dosage to be non-toxic for a pediatric and geriatric population where there is a risk of ingestion of the medicant or any removable plasticized material.
From the foregoing, it will be appreciated that what is needed in the art are topical compositions which will effectively penetrate the skin's barrier, delivering effective relief from both localized and generalized pain, without the need for expensive andlor risky supplemental enhancers such as non-active chemical additives, or electrical, magnetic, or heat stimulation. Further, a method of topical delivery is needed that will effectively deliver the medication over the period needed for penetration without affecting the comfort, safety, or mobility of the patient.
Accordingly, it is a primary object of the present invention to provide safe and effective localized and generalized pain relief through topical delivery of therapeutic agents.
It is a further object of the present invention to provide a means of delivering effective dosages of therapeutic agents transdermally.
A still further object is to provide pain relief topically, and thereby without the risks of sedation and cognitive effects associated with orally administered pain relievers and muscle relaxants.
Another object is to provide pain relief to geriatric, pediatric, and cancer patient populations unable to tolerate orally administered medications.
Yet another object is to provide pain relief to patients who have not achieved adequate pain control/management via oral medications (e.g. amputee).
Still another object is to provide means for delivering effective dosages of therapeutic agents to sites of localized pain and inflammation.
Another object of this invention is to maintain relatively constant dosages of therapeutic agents to sites of pain.
Yet another object of this invention is to provide a protective, comforting cover to sites of local manifestation of pain and/or inflammation.
Another object of this invention is to provide a flexible, protective wrap which will deliver effective dosages of medication without inhibiting patient mobility.
A final object is to provide a controlled-released therapeutic wrap constructed of inexpensive materials.